As most of you seem to have Voodoos, like me, i would recommend getting a compatible TV-tuner card and looping the mobo Composite output to Composite In on the TV card. That way you can play WHD Load games in whatever screenmode you set up in P96.
If the TV card has S-Video In, you could even use that, if you got an RGB > S-Video converter for the mobo's RGB Out.
Failing all that, you can at least get around the 50Hz issue by using WHD Load and the NTSC tool type.